Inner joins Suppose there are 2 tables A and B .if the data is present in both the tables then it will show up after you apply inner join Left outer join All the data in table A will show up matching with the table B .rows which do not match with column A will show up as null Right outer join All data present in B will show up and data which matches with rows in B with table A will show values and data which doesn't match with rows of B table will display as. Null. Full outer join All the values from A and B will show up .matching data from A and B will have vales and data not matching will have null values